All these hinges that are also commercially available have the disadvantage to use screws either to fasten the rod unit to the wire or to retain the hinge member in the bearing aperture of the rod unit. As the jaws move forward and backward, the screws have the tendency to become loose. If the screw is used to fasten the wire, another drawback consists in that the masticatory load, already under normal jaw movements, provides a tremendous amount of pressure acting onto the wire at the contact area with the screw, thus resulting in a metal fatigue and eventual breakage of the wire. The use of a screw implies also that very fine threads have to be manufactured which constitutes a relatively costly procedure. In many cases, the use of a screw results in a bulky construction which causes an irritation of the soft tissue. If the screw is connected to the wire, the lateral movement of the rod unit is restricted, thus increasing the patient's discomfort. Certainly, in U.S. Pat. No. 4,583,944 there is a hinge member consisting of a stud that is connected to a tube extending normally to its smaller shank. There is no screw and no separate part. However, such a design is not only bulky and, therefore, disagreable to the patient, but it is also difficult to manufacture, because the tube will usually be connected to the stud by soldering. Even if it were produced by other methods, it would always involve difficulties. Moreover, the telescopic unit of the Herbst appliance can only be stripped over the head portion of the stud, thus allowing that it can be stripped off by movements of the patient's jaws. Therefore, it never came into practice.